Schiphol airport Amsterdam, what to expect when transferring between Schengen Area countries

No, if your passport is checked in Iceland, then on arrival at AMS, you simply walk off the plane, and proceed to your gate for Rome, all within the Schengen terminal. Without checked bags, the time is fine, if you have checked bags going on to Rome, it is possible they may miss the flight though.

Will I still need to go through passport control, or customs?

No.

Is a hour and a half layover enough time, or should I start trying to rebook my travel plans through Schiphol?

Yes as long as the first flight is on time. Which airline are you flying? Is it Iceland Air and then KLM?
If so KLM has five flights a day in May to Rome from Amsterdam. I would not be concerned this far in advance a lot can change.

Also is this one ticket Reykjavik to Rome or two separate tickets Reykjavik to Amsterdam and Amsterdam to Rome?

The issues you read about mostly concerned those departing from Schiphol. Transfers weren’t impacted that much. Assuming you booked this all on 1 ticket, all you have to do is walk to the next gate. No security, no passport control, no customs.

Hello again,

I should have mention, I have no checked baggage.
Also, I'm flying Icelandair and KLM.

Thank you all for your replies. I think I was 'over worrying' this flight connection. :)

Cheers to all.

To answer Jazz+Travels question, the tickets are separate:
Icelandair Denver->Reykjavik->Amsterdam
KLM Amsterdam->Rome.

Regards,
Bruce

Separate tickets have some risk, if you miss the flight, they are not obligated to rebook you, and it will cost you. I would be checked in online before getting to AMS for the KLM flight. So download the KLM app, you can also stop at a kiosk and get a physical boarding pass for the KLM flight if you will not have data coverage.

It’s a good thing you don’t have luggage, because there’s no way you would make this connection if you had to leave the secure area of the airport to claim and recheck your luggage. Make sure you check in online for your KLM flight before you leave Denver, so you’ll have your boarding pass in hand when you arrive in Amsterdam. Online check in for KLM opens 30 hours before departure, so you should have time to do that before departing Denver.
As already explained by Paul, if your incoming flight into Amsterdam is delayed and you miss your flight to Rome, you’re on your own. Neither KLM nor Icelandair have any responsibility in getting you to Rome. That’s the risk you took by booking this on 2 separate tickets. I’m assuming you booked this on 2 separate tickets to save money. I do hope these savings make up for the additional risk. But mostly I do hope you make your flight!!

I wish you hadn’t gotten separate tickets; you put yourself in jeopardy especially with a tight connection. At least you are not checking any bags. If your arriving flight from Iceland is late and you miss your flight to Rome, if that’s a round-trip between Rome and Amsterdam, your return trip to Amsterdam will be cancelled automatically.